The first objective of the present study was to describe within the proposed database the cases of mutual misunderstanding between native and non-native speakers of Japanese found in their linguistic contact. The proposed database included an exhaustive set of elements which presumably described the causes, ways and results of all the collected cases under survey.Once such database is completed, it would become possible to pursue the second objective, namely, to propose a set of hypotheses concerning the mechanisms of mutual misunderstanding whereby the linguistic contact of the mixed native language groups inevitably brings forth. Then follows the third objective in quest of the possible means to predict and prevent such misunderstanding. The research team did its best in compiling the database of the cases concerning the respective languages. In addition to the first round of data search in published materials, several methods of data elicitation, such as questionnairs, interviews and written reports, were added to increase the variety to the data. The form of the database has been rewritten several times in order to incorporate all the collected cases. The items in the database were selected in accordance with the methodology and hypotheses in the field of linguistic ethnology.On the bases of the present study, the research team will plan to renew the project in pursuit of the second and the third objectives.最終的には各言語担当者によって収集された誤解の事例は統合されたデータ・ベースとして完成をみている。これは上記第一の目的にかなうものである。本研究はさらに第二・第三の目的にむけて再出発する計画である。